No citizen possessing all other qualifications which are or may be prescribed by law shall be disqualified for service as grand or petit juror in any court of the United States, or of any State on account of race, color, or previous condition of servitude; and whoever, being an officer or other person charged with any duty in the selection or summoning of jurors, excludes or fails to summon any citizen for such cause, shall be fined not more than $5,000.